class file for org.reactivestreams.Publisher not found while compiling example from RxJava?

Question

The following code

package com.inthemoon.snippets.rxjava;

import io.reactivex.*;

public class HelloWorld {

   public static void main(String[] args) {
      Flowable.just("Hello world").subscribe(System.out::println);
   }

}

causes the following compile error

Error:(9, 15) java: cannot access org.reactivestreams.Publisher class file for org.reactivestreams.Publisher not found

POM dependency is following

<dependencies>
        <!-- https://mvnrepository.com/artifact/io.reactivex.rxjava2/rxjava -->
        <dependency>
            <groupId>io.reactivex.rxjava2</groupId>
            <artifactId>rxjava</artifactId>
            <version>2.0.4</version>
        </dependency>


    </dependencies>

Anjelicaanjou

have you tried adding reactive-streams explicitly to your maven dependencies ? – Nescience

Yes, now tried. It works either with .final explicit or iv RxJava 2.0.3 – Anjelicaanjou

The same dependency 2.0.4 works fine for me ... maybe get rid of the dependency and do a -U to force updating dependencies .. then adding the 2.0.4 again ... – Nescience

Answer 1

Same error and simple solution - add this to your app Gradle file

implementation 'io.reactivex.rxjava2:rxjava:2.1.14'
implementation 'io.reactivex.rxjava2:rxandroid:2.0.2'

Internecine

Perfect! Thank you. rxjava was missing from my gradle. – Baez

It is strange as I have a project 8 month old where just a second line (second import) was enough to work well and the new project has issue similar to topic starter. – Yeung

Got a though this dependency migh went implicitly with some other dependency in that first project – Yeung

While adding kotlinx.coroutines.flow.Flow flow in room I got this error and after adding the above mentioned implementation, its fine, however how is Kotlinx Flow and rx are related in this case – Ramsden

Answer 2

The same happened to me.I have solved it. add the dependeny follows:

<dependency>
    <groupId>org.reactivestreams</groupId>
    <artifactId>reactive-streams</artifactId>
    <version>1.0.0</version>
</dependency>

Premier

Answer 3

This has been fixed since 2.0.5 by github.com/ReactiveX/RxJava/issues/5014 2.1.1, is the latest version as of this answer

Solution :

    <dependency>
        <groupId>io.reactivex.rxjava2</groupId>
        <artifactId>rxjava</artifactId>
        <version>2.1.1</version>
    </dependency>

Gavial

adding some explanation would be really necessary – Semblance

so editing your answer to improve it would be better than a comment. – Semblance